Clarify catch-all route usage

Author: taion

upgrade-guides/v1.0.0.md

@@ -87,7 +87,7 @@ Named routes are gone (for now, [see discussion](https://github.com/rackt/react-
 
 ### NotFound route
 
-Not found really confused people, mistaking not finding resources
+"Not found" really confused people, mistaking not finding resources
 from your API for not matching a route. We've removed it completely
 since it's simple with a `*` path.
 
@@ -99,6 +99,8 @@ since it's simple with a `*` path.
 <Route path="*" component={NoMatch}/>
 ```
 
+As this catch-all route will match everything, it must be the last route specified in the child route array.
+
 ### Redirect route
 
 ```js